Fuse plug



Dec. 27, 1932. RUMMLER 1,891,951

FUSE PLUG Filed May 25, 1932 r 2 Sheets-Sheet l Patented Dec. 27, 1932 UNITED STATES I aosnrn M. nniunrnn,

FUSE

Application filed May 25, 1932. Serial No. 613,438.

This invention relates to multiple fuse plugs and particularly to a multiple fuse plug that gives a mechanical indication when a fuse element has burned out.

The object of this invention is to provide a multiple fuse plug having a visible mechanical means incorporated therein, to readily indicate when a fuse element is burned out.

An illustrative embodiment of this invention is shown in the accompanying drawings, in which I Figure 1 is a side viewof the inverted cupshaped member.

Figure 2 is a side view of the'ro-tor.

Fig. 3 is a side view of the cap for the cupped member, and showing the details of the pin terminal.

Fig. 4 is a side view of a contact band partly shown in section.

Fig. 5 is a side view of a threaded metallic shell partly shown in section.

Fig. 6 is a sectional detailed view of the assembled fuse plug in closed or operating position.

Fig. 7 is a sectional detailed View of the fuse plug in open or inoperative position with the shell and contact band omitted.

Fig. 8 is a sectional view taken on the line 8-8 of Fig. 6. Y I

Fig. 9 is a side View of a fuse element. Fig. 10 is a face view of a fuse element. Fig. 11 is a sectional view of the cupped member, showing the fuse elements in place. Fig. 12 is a top view of the assembled fuse r plug.

" Referring in detail to the drawings, the fuse plug comprises an inverted cup-shaped member 1, preferably made of dielectric ma terial, having upstanding segmentary peripheral bosses 2 serving as threads. The side wall of the member 1 is provided with concave depressed rim segments 3 and its interior surface is provided with a plurality of angularly spaced longitudinal grooves 4 which register with the rim segments. The interior surface is also provided withan annular inwardly projecting wedge-shaped shoulder 5, forming an annular V-shaped groove which terminates the inner ends of the grooves 4. The cap or, base 6 which closes the open end of the member 1 and is preferably made of dielectric material, is provided with convex projecting rim segments 7 to interfit with the concave rim segments 3 of the cupped member 1; and a metallic pin terminal 8 which extends centrally through the base 6 and has at one end a metallic button 9 adapted to abut against the outer side of said base and form a contact point. A helical compression spring 11 surrounds the pin terminal 8 and is secured at one end to an interior flexible metallic brush 10, slidably mounted on the upper end of the pin terminal, and at the other end rests against a bearing 12. 'The bearing 12 also ierves to lock the pin terminal button 9 to ase.

The brush 10 extends laterally from the pin terminal 8 and itsfree end is curved or bent to form a smooth riding, spring tensioned, contact element for individually and selectively contacting or engaging the U- shaped fuse elements 22 which are positioned in thegroo-ves 4 of the member 1. effectively shown in Figs. 6 and 8.

The pin terminal 8 is surrounded by a hollow rotor 13 which is provided with an inverted L-shaped aperture 14, see Fig. 2, for receiving and carrying the brush 10. One end of the rotor 13 is provided with a neck or handle 15 which is inserted through the aperture 16 in the member 1, and by this means the rotor can be manually turned to shift the brush 10 for selectively contacting the fuse elements 22.

' The rotor 13 is so proportioned that it will be freely journaled within the member land easily rotatable without any unnecessary wobble or side play. Also the length of the rotor 13 is proportioned so as to permit a limited longitudinal or axial movement within the member 1. The spring 11 acting against the brush 10, which extends through and is carried by the rotor, constantly urges the rotor outwardly and a shoulder 17 formed by the margin ofthe aperture 16 pro vides a stop for limiting such outward movement. p g g The fuse elements 22 are U-shaped as shown in Figs. 6, 9 and 11, and are provided This is with wedge-shaped stops 18 formed on one end and tapering inwardly toward the wall of the member 1. Also the bottom or bent portion of the fuse elements is curved inwardly to seat in the concave depressed seg ments 3.

Figures 1 to 5 inclusive represent the five main parts of a fuse plug arranged in position to be assembled, with the exception of the fuse elements which are shown in Figs. 9 and 10. In assembling the fuse plug, the rotor 13, Fig. 2, is placed on the cap or base 6 as assembled and shown in Fig. 3, the brush 10 being guided into the inverted L- shaped aperture let. The fuse elements 22 are then placed in the grooves 4 of the mem her 1, as shown in Fig. 11, so that the wedgelike stop end is disposed on the inside of the member 1 and the opposite end or leg is disposed on the outside of the member 1, the curved bottom portion being seated in the depressed segments 3. v

The assembled rotor 13 and cap 6 are then inserted into the member 1 with the brush 10 riding on, or contacting the side wall of the member 1 between any pair of the fuse elements 22. The convex or projecting rim segments 7 of the base 6 will then abut and seat in the concave or depressed rim segments 3 of the member 1, and securely clamp the fuse elements 22 against lateral or longitudinal displacement. The contact band 19, Fig. 4, is now placed around the member 1, so that threads 2 on the member 1 protrude beyond the surface of contact band 19, through the spaces 21 provided for that purpose, see Fig. 4.

The threaded metallic shell 20, Fig.5, is then screwed onto the member 1, Fig. 1, and the fuse plug is now assembled with the parts in a position similar to that shown in Fig. 7, the shell 20 being soldered to the band 19 to make a permanent and rigid con nection.

To place the plug in operable condition, the handle 15 is pressed downwardly against the action of the spring 11 and turned to the position shown in Fig. 12, so that brush 10 is in position to engage the stop 18 of the first fuse element 22. The handle 15 is then released, the brush 10 engaging the fuse 22 with pressure contact under the action of the spring 11, and the fuse is ready for use.

In operation the fuse plug is inserted into a fuse box such as is commonly used, and the handle 15 is turned to the position shown in Fig. 12. The brush now assumes the position shown in Fig. 6. W'hen the contacted fuse element 22 burns out the sprin 11, having been compressed, forces what is left of the upper part of the fuse element outwardly with the aid of the brush 10, and ams it into the V-shaped groove between the shoulder 5 and the wall of the member 1 so that it will be retained there. At the same time the brush 10 also forces the rotor outwardly into the position shown in Fig. 7.

To reset the fuse, the handle 15 is pressed inwardly and turned clockwise until the ar row on the top of the handle points to the numeral 2 shown in Fig. 12. This action again brings the brush into a position similar to that shown in Fig. 6. The resetting operation is repeated each time the contacted fuse element burns out and until all six of the fuses are used.

It will be apparent from the foregoing that it is not necessary to take the fuse plug out and inspect it when the fuse element burns out as is frequently necessary where more than one fuse is used in afuse box. Where there are a number of fuses in a single box, fuses embodying the present invention that have burned out may be immediately de tected by the handle, which protrudes further than the others, and may immediately be adjusted or reset by a simple movement of the hand.

Although but one specific embodiment of this invention is herein shown and described, it is to be understood that details of the construction shown may be altered or omitted without departing from the spirit of the invention as defined by the following claims:

I claim:

1. A multi-fuse structure comprisin Y a hollow body member, a rotor mountet in said body member and axially shiftable relative thereto, fuse elements disposed within said body member between said rotor and the inner wall of said body member, means urging said rotor axially relative to said body member, means carried by said rotor for selectively contacting said fuse elements, a terminal having connection with said last named means, and a second terminal having connections with said fuse elements collectively.

2. A multi-fuse structure comprising a. hollow body member, a rotor mounted in said body member and axially shiftable relative thereto, fuse elements disposed within said body member between said rotor and the inner wall of said body member, means urging said rotor axially relative to said body member, means carried by said rotor for selectively contacting said fuse elements, releasable means controlled by said fuse elements restraining axial movement of said rotor, a terminal having connection with said last named means, and a. second terminal having connections with said fuse elements collectively.

3. A multiple fuse structure comprising an inverted cup-shaped member having longitudinal grooves therein, a rotor journaled in said cup-shaped member and axially shiftable relative thereto. a cap for said cupshaped member, a pin terminal secured to said cup and extending into saidrotor and cup-shaped member, means urging said rotor outwardly from said cup-shaped member, an

interior brush on said terminal, fuse elements in said grooves arranged to be engaged individually by said brush, and an exterior shell on saidcupshaped' member having contact with the ends of said fuse elements.

4:. A multiple fuse structure comprising an inverted cup-shaped member having longitudinal grooves therein, a rotor journaled in said cup-shaped member and axially shiftable relative thereto, a cap for said cupshaped member, a pin terminal secured to said cap and extending into said rotor and cup-shaped member, means urging said rotor outwardly from said cup-shaped member, an interior brush on said terminal, fuse elements in said grooves arranged to be selectively engaged by said brush, means controlled by said fuse elements to resist outward movement of said rotor, and an exterior shell on said cup-shaped member contacting the ends of said fuse elements, all arranged and adapted to provide visible mechanical indication when one of said fuse elements burns out.

5. A multiple fuse structure comprising an inverted cup-shaped member having longitudinal grooves therein, a rotor journaled in said cup-shaped member and axially shif able relative thereto, a shoulder on the interior of said cup-shaped member for limit- 5 ing the outward movement of said rotor, a

cap, a pin terminal secured to said cap and extending into said cup-shaped member, an interior brush on said terminal, means urging said brush axially along said terminal, fuse elements in said grooves selectively engaged by said brush, means resisting axial movement of said brush, anda shell on said cupshaped member contacting the'ends of said fuse elements.

6. A multiple fuse structure comprising an inverted cup-shaped member having longitudinal groovestherein, a rotor journaled in said cup-shaped member and axially movable relative thereto, a shoulder on the in terior of said cup-shaped member for limiting the outward movement of said rotor, av cap, a pin terminal secured to said cap and extending into said cup-shaped member, a compression spring in said cup-shaped member for urging said rotor outwardly, an interior brush on said terminal, fuse elements in said grooves and arranged to be selectively contacted by said brush. means normally resisting the outward movement of said rotor, and a shell surrounding said cupshaped member and contacting the ends of said fuse elements.

7. A multiple fuse structure comprising an inverted cup-shaped member having longitudinal grooves therein, a rotor journaled in said cup-shaped member, a shoulder on the interior of said cup-shaped member for limiting the outward. movement of said rotor, a base, a pin terminal secured to said base, a spring for urging said rotor outwardly, an interior brushpivotally and slidably attached to said terminal, fuse elements in said grooves, said fuse elements being provided with means forming stops on one of their ends'for engaging said brush, and an exterior shell surrounding said cup-shaped member and contacting the ends of said fuse elements. r

8. A multiple fuse structure comprising an inverted cup-shaped member having depressedrim segments and having longitudinal grooves therein registering with said Q rim segments, a cap having '"projectingrim segments to mterfit with the said depressed rim segments of said cup-shaped member, an

annular shoulder on the interior ofsaid cu shaped member positioned at the inner ends of said grooves, a rotor journaled 111 said cupshaped member, a pin terminal secured to said cap and extending in said plug, an'interior brush on sald pin terminal extending through a slot 1n said rotor and movable therewith, a compression spring for urging notched rim segments and having longitudinal grooves therein reigstering with said rim segments, a base having projecting rim segments to interfit in said notched rim segments of said cupped member, a rotor journaled in said cupped member, a shoulder at the outer end of said cupped member for limiting the outward movement of said rotor, a pin terminalsecured to and extending through said base, means secured adjacent one end of said terminal adapted to form a bearing surface, a compression spring seated on said bearing surface for urging said rotor outwardly, an interiorbrush mounted on the other end of said terminal, fuse elements in said grooves, means on one end of each of said fuse elements adapted to form stops engaged by said brush to resist the action of said spring, and

an'outer metallic shell on said cupped member cupped member terminating said grooves, a

rotor journaled in said cupped member, a

pin terminal secured to said base, fastening means secured adjacent one end of said terminal andadapted to form a bearing surface, an interior brush pivotally mounted adja- 5 cent the other end of said terminal, a compression spring surrounding said terminal and bearing at one end against said fastening means and at the other end against said brush to urge said brush longitudinally outward, 70 fuse elements positioned in said grooves and extending through said rim segments to the outside of said cupped member, said fuse elements being provided with stops at their inner ends adapted to be engaged by said brush 5 to resist the tension of said spring, a threaded metallic shell surrounding a portion of said cupped member, and a contact band interposed between said cupped member and shell forming a contact plate between the outer end portions of said fuse elements and said shell.

11. A fuse,comprising a hollowcup-shaped member having an aperture in its closed end and a plurality of longitudinally extending angularly spaced grooves in its inner Wall surface, a rotor journaled in said cup-shaped member and having a reduced portion projecting through said aperture, a cap closing the open end of said cup-shaped member, a terminal pin extending through said cap and into said rotor, a fuse element in each of said spaced grooves, said fuse elements extending over the rim of said cup-shaped member and along its outer side, a brush mounted on said terminal pin adj acent its inner end and extending laterally through said rotor to contact selectivelysaid fuse elements,means urging said rotor axially of said terminal pin and toward the closed end of said cup-shaped member, means on said fuse elements engaged by said brush and resisting said axial movement of said rotor, means on said cup-shaped member limiting said axialniovement of said rotor, and a shell surrounding said cup-shaped member and contacting the outer ends of said fuse elements.

Signed at Chicago in the county of Cook and State of Illinois this 23rd day of May, 1932.

JOSEPH M. RUMMLER. 

